Hyaluronic acid has been used as a moisturizing agent in cosmetics as well as a drug in ophthalmology, orthopedic surgery and dermatology etc. While hyaluronic acid can be produced from extracts of animal tissues, such as cock's comb and the vitreous body of cattle eyes, contaminants such as chondroitin sulfate be mixed in and hyaluronidases present in tissues can easily break down hyaluronic acid into low molecular weight substances, so hyaluronic acid has also been produced from culture media obtained by culturing microorganisms capable of producing hyaluronic acid (fermentation process) (Patent Document 1). Compared to the extraction process, the fermentation process allows hyaluronic acid to be produced from a fixed raw material using a fixed method, which keeps the quality of the product at a certain level, and therefore has greater industrial utility.
Further, in order to produce hyaluronic acid industrially, fermentation processes in which various culture medium components are used for fermentation have been developed (Patent Documents 2 to 4). Patent Document 2 describes a fermentation process in which a culture medium with increased amounts of eight types of amino acids generally considered to be necessary for growth is used as the effective component in hyaluronic acid production. Additionally, Patent Document 3 describes a fermentation process in which a culture medium with increased amounts of arginine and/or glutamic acid is used. Additionally, Patent Document 4 describes a fermentation process in which a culture medium with an increased amount of arginine is used.    Patent Document 1: JP-B H4-12960    Patent Document 2: JP-A H7-46992    Patent Document 3: JP-A S62-289198    Patent Document 4: JP-A 563-141594